[rescue] IBM on ebay

[dave at cca.org]

james at foonly.com writes:

>On Mon, 13 May 2002 dave at cca.org wrote:

>> Aside from the obvious performance issues, wasn't that AT/390 thingy
>> actually not fully compatable?

>There was no AT/390.  The AT/370 was a 2 ISA board mutant that implemented
>most of the 370 instruction set in microcode on a modified mask 68000, and
>emulated some of the rest with a vanilla 68000.  It didn't have full
>support for priv instructions and only ran a single user version of
>VM/CMS.

Ah....

Did it emulate the IO processors?

Did IBM fab the mutant 68K, or did Moto do it?

>The smallest /390 is probably the P/390 or R/390, essentially one-card
>PCI or microchannel implementations of the 390 arch.  They make
>respectable development systems, I would have loved to have had one when I
>was doing MVS application development.

Interesting.

So you could put a 390 CPU in an RS/6000, and use the POWER CPU as
an IO processor for the 390... Deja Vu! 

------ David Fischer ------- dave at cca.org ------- http://www.cca.org ------
-------- "I prefer the ridiculous to the sublime." - James Chance ---------